Physiological information is useful for self-monitoring of one's personal health and fitness. Monitoring a person's physiological characteristics can be used to provide biofeedback about one's physiological state. A biofeedback device makes information about bodily processes perceptible to the senses, allowing the person to interpret the biofeedback information and react or alter one's activity in order to help control one's involuntary bodily processes. Various physiological characteristics can be monitored during physical activity or other activities. For example, a heart rate monitor is worn on the body to continuously or periodically measure heart rate. The heart rate can be transmitted to a device, such as a computer, which processes the signal and displays the heart rate information in the form of text, numbers, or a graph.
Wearable devices for receiving and displaying physiological information are often complicated devices displaying alphanumeric text to communicate a multitude of data points and statistics. Complex display devices, such as performance watches, display various types of personal data, such as heart rate as beats per minute or as a percentage of maximum heart rate, calories burned, time lapsed, lap time, lap count, distance, speed, acceleration, pace, pedal rotations or cycling cadence, elevation, altitude, incline, temperature, and other information about a person's activity or environment. Information is typically displayed in the form of alphanumeric text or in a graphical manner. Digital text, numbers, and charts displayed on a relatively small display screen, such as on a watch face, can be difficult to read and interpret during physical activity. Complex wearable devices are bulky and can contain an overwhelming amount of data that can actually interfere with the user's performance during an activity, rather than enhance performance. The device may take a user's attention away from an activity for several seconds while the user views the data. The distraction caused by a complex display of information can be merely interruptive, but can also be dangerous, for example, when a user takes his or her eyes off of the road.
Fitness and sport watches, for example, often include blinking lights or notification sounds or vibration to alert the user to a particular parameter or end point. However, intrusive lights and sounds are disruptive to certain types of activities and exercise. Other wearable devices record physiological data, but require a computer in order to upload and display the data after an activity. A user receives performance data after the activity and after the time has passed when the user can react and use the performance data. While past physiological data is useful for some purposes, real-time monitoring is more useful to allow the user to adjust his or her performance during an activity.